CA1316641C

CA1316641C - Stable biodegradable fabric softening compositions containing 2-hydroxypropyl monoester quaternized ammonium salts

Info

Publication number: CA1316641C
Application number: CA000591911A
Authority: CA
Inventors: Frederick E. Hardy; Darlene R. Walley
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 1988-02-25
Filing date: 1989-02-23
Publication date: 1993-04-27
Anticipated expiration: 2010-04-27
Also published as: EP0330261A3; EP0330261A2; JPH0241469A; US4840738A

Abstract

STABLE BIODEGRADABLE FABRIC SOFTENING COMPOSITIONS

QUATERNIZED AMMONIUM SALTS
ABSTRACT
Shelf-stable biodegradable fabric softening compositions are provided comprising mixtures of a quaternized ester-ammonium softening compound having the formula and mixtures thereof, wherein each R substituent is independently selected from C1-C6 alkyl, alkenyl or hydroxyalkyl groups, R1 is a C14-C22 hydrocarbyl group, R2 is a C13-C21 hydrocarbyl group, and A is a softener compatible anion; and a liquid carrier. These biodegradable compositions have improved product stability and dispersability, as well as excellent fabric softening characteristics.

BSH/jp(BAP4:3792a)

Description

~3166~

STAi3LE BIODEGRADABLE FABRIC SOFTENING COMPOSITIONS

QUATERNIZED AMMONIUM SALTS
Frederick E. Hardy s Darlene R. Walley TECHNICAL FIELD
The present invention relates to textile treatment composi-tions. In particular, it relates to textile treatment compositions for use in the rinse cycle of a textile laundering operation to provide fabric softening/static control benefits, the compositions being characterized by excellent storage stability and viscosity characteristics, as well as biodegradability. The compositions herein can also be used to treat fabrics in hot air clothes dryers and in through-the-wash compositions, as well as in hair conditioner compositions.
BACKGROUND OF THE INVENTION
Textile treatment compositions suitable for providing fabric softening and static control benefits during laundering are well-known in the art and have found wide-scale commercial applica-tion. Conventionally, rinse-added fabric softening compositions contain, as the active softening component, substantially wa-ter-insoluble cationic materials having two long alkyl chains.
Typical of such materials are di-tallow di-methyl ammonium chloride and imidazolinium compounds substituted with two stearyl groups. These materials are normally prepared in the form of a dispersion in water. It is generally not possible to prepare such agueous dispersions with more than about 10% of cationic materials without encountering intractable problems of product viscosity and stability, especialiy after storage at elevated temperatures, such that the compositions are unpourable and have inadequate dispensing and dissolving characteristics in rinse water. This physical restriction on softener concentration naturally limits the Jevel of softening performance achievable without using excessive amounts of product, and also adds substantially to the costs of distribution and packaging. Accordingly, it would be highly desirable to prepare physically-acceptable textile treatment .

- 2 - ~ 3 1 6 6 4 1 compositions containing much higher levels of water-insoluble cationic softener materials.
It would also be desirable to have fabric softening composi-tions which are storage-stable, and also which are biodegradable.
5 However, materials which may be biodegradable are often difficult to formulate as stable liquid compositions.
It is an object of this invention to provide a storage-stable, biodegradable fabric softening composition. It is a further object to provide such materials in the form of liquid products, 10 including concentrates, suitable for use in the rinse cycle of a textile laundering operation, and in sheet form for use in clothes dryers. These and other objects are obtained using the present invention, as will be seen from the following disclosure.
Cationic softener materials are normally supplied by the 15 manufacturer in the form of a slurry containing about 70~-80~ of active material in an organic liquid such as isopropanol, sometimes containing a minor amount of water (up to about 10%) . Retail fabric softening compositions are then prepared by dispersion of the softener slurry in warm water under carefully controlled 20 conditions. The physical form and dispersibility constraints of these industrial concentrates, however, are such as to preclude their direct use by the domestic consumer; inde~d, they can pose severe processing problems even for the industrial supplier of retail fabric softening compositions.
The use of various quaternized ester-amines as cationic fabric softening agents is known in the art. See, for example, U.S. Patent 4,339,391, Hoffmann, et al., issued July 13, 1982, for a series of quaternized ester-amines which function as fabric softeners. Various quaternized ester-amines are commercially available under the trade marks SYNPROLAM FS from ICI and REWOQUAT from REWO . Simi larly, methods for preparing various quaternized ester-amine compounds are known in the art. See, for example, U . S. Patent 3,342,840, Sobolev, issued September ~ 9, 1967, U . S . Patent 3,872,1 38, Ogatu, issued March 18, 1975, and Japanese Laid Open Publication 49-1510, assigned to Gosei Chem. Ind . Co., published ~anuary 9, 1974.

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Unfortunately, although quaternized ester-amines are believed to be rapidly biodegradable, they are more subject to hydrolysis than are conventional cationic softening agents le.g., ditallow dimethyl ammonium chloride and analogs thereof) and 5 hence can encounter hydrolytic stability problems upon prolonged shelf storage. The product stability and viscosity problems become increasingly more unmanageable in concentrated aqueous dispersions .
Various solutions to the problem of preparing concentrated 10 fabric softening compositions suitable for consumer use have been addressed in the art. See, for example, U.S. Patents 4,426,299, issued January 17, 1984, and 4,401,578, issued August 30, 1983, Verbruggen, which relate to paraffin, fatty acids and ester extenders in softener concentrates as viscosity control agents.
15European Patent 0,018,039, Clint, et al., issued March 7, 1 984, relates to hydrocarbons plus soluble cationic or nonionic surfactants in softener concentrates to improve viscosity and stability characteristics.
U.S. Patent, 4,454,049, MacGilp, et al., issued June 12, 20 1984, discloses concentrated liquid textile treatment compositions in the fcrm of isotropic solutions comprising water-insoluble ; di-C16-C24 optionally hydroxy-substituted alkyl, alkaryl or alkenyl cationic fabric softeners, at least about 70% of the fabric softener consisting of one or more components together having a 25 melting completion temperature of less than about 20C, a water-insoluble nonionic extender, especially C -C
hydrocarbons or esters of mono- or polyhydric alcohols with C8-C24 fatty acids, and a water-miscible organic solvent. The concentrates have improved formulation stability and 30 dispersibility, combined with excellent fabric softening characteristics .
U. S . Patent 4,439,330, Ooms, issued March 27, 1984, teaches concentrated fabric softeners comprising ethoxylated amines.
U, S. Patent 4,476,031, Ooms, issued October 9, 1984, 35 teaches ethoxylated amines or protonated derivatives thereof, in combination with ammonium, imidazolinium, and like materials.

~' , . . .

" ~3166~1 The use of alkoxylated amines, as a class, in softener compositions is known (see, for example, German Patent Applications 2,829,022, Jakobi and Schmadel, published January 10, 1980, and 1,619,043, Mueller et al., published October 30, 51969, and U . S. Patents 4,076,632, Davis, issued February 28, 1978, and 4,157,307, Jaeger and Davis, issued June 5, 1979) .
U.S. Patent 4,422,949, Ooms, issued December 27, 1983, relates to softener concentrates based on ditallow dimethyi ammonium chloride (DTDMAC), glycerol monostearate and 10 polycationics.
In United Kingdom Application 2,007,734A, Sherman et al., published May 23, 1979, fabric softener concentrates are disclosed which contain a mixture of fatty quaternary ammonium salts having at least one C8-C30 alkyl substituent and an oil or 15 substantially water-insoluble compound having oily/fatty properties. The concentrates are said to be easily dispersed/emulsified in cold water to form fabric softening compositions .
Concentrated dispersions of softener material can be pre-20 pared as described in European Patent Application 406 and UnitedKingdom Patent Specification 1,601,360, Goffinet, published Octo-ber 28, 1981, by incorporating certain nonionic adjunct softening materials therein.
As can be seen, the various solutions to the specific problem 25 of preparing fabric softening compositions in concentrated form suitable for consumer use have not been entirely satisfactory. It is ~enerally known (for example, in U.S. Patent No. 3,681,241, Rudy, issued August 1, 1972) that the presence of ion;zable salts in softener compositions does help reduce viscosity, but this ap-30 proach is ineffective in compositions containing more than about12~ of dispersed softener, inasmuch as the level of ionizable salts necessary to reduce viscosity to any substantial degree has a seriously detrimental effect on product stability.
It has now been discovered that fabric softener compositions, 35 especially concentrated compositions, containing the speci fic quaternized hydroxypropyl monoester ammonium salts of the 13166~
present invention possess desirable product stability and viscosity characteristics. Moreover, neither the use of these speci~ic compounds in laundry fabric softening compositions~ nor the desirable fabric 5 softener/viscosity/stability/biodegradability properties of fabric softening compositions containing these compounds, including concentrates, appear to have been appreciated heretofore.
SUMMARY OF THE INVENTION
The present invention relates to a shelf-stable/biodegradab]e fabric 0 softening composition comprising:
(a) from about 1% to about 20% by weight of submicron-sized particles of a quaternized ester-ammonium softening compound having the formula R OH O
R- + -CH 2 -CH -CH 2 -O-C- R A
and mixtures thereof, wherein each R substituent is independently selected 5 from C,-C6 alkyl, alkenyl or hydroxyalkyl groups, Rl is a Cl4-C~ hydrocarbyl group, R2 is a Cl3-C2, hydrocarbyl group and, A is a softener compatible anion; and (b) from about 60% to about 98% of a liquid carrier having said softening compound particles dispersed therein; said composition being 20 maintained at a pH ranging from about 2.0 to about 5.0 and further being substantially free of unprotonated amines.
The liquid carrier is typically water, preferably a mixture of a C,-C4 monohydric alcohol and water.
While not intending to be limited by theory, it is be}ieved that the ester 2 5 moiety lends biodegradability to these compounds, whereas the fact that onlya single ester group is present provides sufficient hydrolytic stability that the compounds can be stably formulated as liquid compositions, under the conditions disclosed hereinafter. The desirable viscosity characteristics of thecompounds which allows them to be formulated as concentrates are 30 une~pected. Moreover, since the compounds are cationic, they provide not only fiber and fabric softness, but also anti-static benefits.

131~6~1 The preferred liquid compositions herein have the softening compound present as particles dispersed in the liquid carrier.
The particles are preferably sub-micron size, generally having average diameters in the range of about 0 .10-0 . 50 microns . Such 5 particle disper~ions can optionally be stabili~ed against settling by means of standard non-base emulsifiers, especially nonionic extenders .
Importantly, the liquid compositions herein are substantially free tgenerally, less than about 1%) of free ti.e., unprotonated) 10 amines, since free amines can catalyze decomposition of the quat-ernized ester-ammonium softening compounds, on storage. If minor amounts of amines are present, they should be protonated with acid during the formulation of the compositions. Strong acids, such as H3PO4 and HCI, can be used for this purpose.
The low viscosities exhibited by dispersions of particles of the softening compounds described herein allow them to be formulated as water-dilutable fabric softener "high concentrates"
which contain from about 11% to about 20% by weight of the fabric softener compound. Such high concentrates may be conveniently 20 packaged in pouches, which can be diluted with water by the user to produce "single-strength" softeners (typically, 3-8 concentration of softener active).
The compounds herein can also be formulated as solids, for example, in combination with particulate carriers as particulate 25 fabric softening and antistatic compositions. When formulated as solids, the pH and presence or absence of amines are, of course, not as critical as with the liquid compositions, since stability to hydrolysis on storage is not so problematic.
Other solid compositions herein have the compounds 30 releasably affixed to sheet materials to provide fabric softening and antistatic compositions in sheet form which can be used in hot air clothes dryers.
The invention also encompasses a method of softening fibers (including hair) or fabrics, or imparting an antistatic finish 35 thereto, comprising contacting said fibers or fabrics with a composition of the above-disclosed type.

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13~6~

All percentages, ratios and proportions herein are by weight, unless otherwise specified.
DETAILED DESCRIPTION OF THE INVENTION
The compositions of the present invention comprise a mixture 5 of a quaternary ester-ammonium fabric softening compound and a liquid carrier.
Quaternized Ester-Ammonium Softenin Compound The present invention contains as an essential component from about 1% to about 20%, preferably from about 29~ to about 10 10%, of a quaternized ester-ammonium softening compound having the formula R OH O

Rl 15 wherein each R substituent is a short chain (C1-C6, preferably C1-C3) alkyl, alkenyl or hydroxyalkyl group, e.g., methyl (most preferred), ethyl, propyl, propenyl, hydroxyethyl, and the like, or mixtures thereof; R is a long chain C14-C22 hydrocarbyl sub-stituent, preferably C16-C18 alkyl, most preferably straight-chain 20 Ci8 alkyl; R is a long chain Ct3-C21 hydrocarbyl substituent, preferably C1 3-C1 7 alkyl, most preferably C1 7 straight chain alkyl. The counterion A is not critical herein, and can be any softener-compatible anion, for example, chloride, bromide, methyl-sulfate, formate, sulfate, nitrate and the like. It will be 25 understood that substituents R, R1 and R2 may optionally be substituted with various groups such as alkoxyl, hydroxyl, or can be branched, but such materials are not preferred herein, In addition, R, R1 and R2 may optionally be unsaturated (i.e., R, R1 and/or R2 may be alkenyl groups). The preferred 30 compounds can ~e considered to be a 2-hydroxypropyl monoester variation of ditallow dimethyl ammonium salts (e.g., DTDMAC, a widely used fabric softener compound).
The above compounds used as the active softener and anti-static ingredient in the practice of this invention are prepared 35 using standard reaction chemistry. For example, in a preferred 131~6~

method of synthesis, a fatty acid of the formula R2COOH is neutralized with a tertiary amine of the formula R1N(R)2 and made into a fatty acid-tertiary ammonium salt which is then reacted with epichlorohydrin to yield the desired reaction product 5 (wherein R, R1 and R2 are as defined above). A method for the synthesis of a preferred softening compound is disclosed in detail hereinafter. However, it will be appreciated by those skilled in the chemical arts that this reaction sequence allows a broad selection of compounds to be prepared, Illustrative, nonlimiting examples of useful quaternked 2-hydroxypropyl monoester ammonium salts (wherein all long-chain alkyl substituents are straight-chain) include:
3121C18H37~JCH2CH(OH)CH20ClO)C17H35Br~

3]2[C~6H331~hCH2CH (OH)CH20C(O)C15H31CI~
IC2H5]2[C18H3516~NCH~CH(OH)CH20C(O)C15H31CI~) [c2H5]lcH3]lcl8H37l~NcH2cH(oH)cH2oc(o)l~l7H35cH;~so4~) 3 7]l 2 sllc16H33l~hcH2cH(oH)cH2oc(o)c1sH
liso-c3H7]lcH3}lc18H37l~NcH2cH(oH)cH2oc( ) 15 31 Since the foregoing compounds are somewhat labile to 20 hydrolysis, they should be handled rather carefully when used to formulate the compositions herein. For example, stable liquid compositions herein are formulated at a pH in the range of about 2.0 to about 5.0, preferably about pH 3.5 + 0.5. The pH can be adjusted by the addition of a Bronsted acid. ~xamples of suitable 25 ~3ronsted acids include the inorganic mineral acids, carboxylic acids, in particular the low molecular weight (C1-C5) car~oxylic acids, and alkylsulfonic acids. Suitable inorganic acids include HOI, H2SO4, HNO3 and H3PO4. Suitable organic acids include formic, acetic, methylsulfonic and ethylsulfonic acid. Preferred 30 acids are hydrochloric and phosphoric acids.
Synthesis of quaternized monoester amine softening compound Synthesis of the preferred biodeqradable, quaternized monoester ammonium softening compound used herein can be accom~lished using the following "one-pot" process:

.

`` g 131664~

C H3 ~-N- ( CH3 ) 2 + Cl 7H3 5C2 2 ` o ' OH o ~ ~
3) 2 N-CH2~ -CH20C-C1 7H35CI ~

g (0.175 mole) of stearic acid and 80 g of isopropanol are placed in a 3-necked, 500-ml round bottom flask equipped with a reflux condenser, and mixed with a magnetic stir bar. 52.7 g (0.175 mole) of dimethyl stearyl amine is added to the stirring 10 stearic acid-isopropanol mixture, followed by the addition of 30 9 of water. The mixture is stirred for appr~ximately ~ hour tuntil a clear solution is obtained). Next, 18.4 g (0.190 mole) of epichlorohydrin is added to the mixture. The temperature is raised to 80C (oil bath) and the stirring is continued for an 15 additional 20 hours.
The reaction mixtùre is cooled to room temperature, and a white precipitate is formed. The solid material is collected on a WhatmanR #1 filter paper (using a Buchi funnel apparatus) and is subsequently recrystallized from hot (60C) isopropanol. The 20 solid material is dried under vacuum (0.2 mm Hg) for 24 hours.
ANALYSIS
TLC (thin layer chromatography): 10x20 cm glass plate, 250 micron silica gel; solvent system, chloroform:methanol:water ~ ' (15:6:0.6; v/vlv); visualization, 5% phosphomolybdlc acid in - 25 ethanol; Rf=0.61.
IR (CC14): 3140, 2920, 2850, 1958, 1724, 1525, 1464, 1210, 1170 cm 1.
1H NMR (CDC13): ~6.02 (lH), 4.6-4.4 (lH), 4.3-4.0 (2H), 3.7-3.3 (10H1, 2.3 (2H), 1.8-1.4 (4H), 1.2 (58H), 0.8 (6H) ppm 30 (relative to tetramethylsilane).
13C NMR (CDC13): ~173.4, 66.4, 66.0, 65.9, 63.5, 52.5, 52.4, 34.3, 31.9, 29.7, 29.5, 29.3, 29.2, 26.6, 25.0, 22.7, 22.6, 14.1 ppm (relative to tetramethylsilane).

Liquid Carrier 1 ~ ~ 6 ~ ~1 The compositions herein comprise a liquid carrier, e.g., water, preferably a mixture of water and a Cl-C4 monohydric alcohol (e.g., ethanol, propanol, isopropanol, butanol, and mix-tures thereof), isopropanol being preferred. These compositions comprise from about 60% to about 98%, preferably from about 70%
to about 95%, of the liquid carrier. Preferably, the amount of the C1-C4 monohydric alcohol in the liquid carrier is from about 59~ to about 50~ by weight of the quaternked ester-ammonium softening compound, the balance of the liquid carrier being 1 0 water.
The softening compounds used in this invention are insoluble in such water-based carriers and, thus, are present as a dis-persion of fine particles therein. These particles are sub-micron, preferably having average diameters of from about 0.1 to about 15 . 5 microns, in size and are conveniently prepared by high-shear mixing which disperses the compounds as fine particles. A
method of preparation of a preferred dispersion is disclosed in detail in Examples l-IV hereinafter. Again, since the softening compounds are hydrolytically labile, care should be taken to avoid 20 the presence of base, and to keep the processing temperatures and pH within the ranges specified herein.
The particulate dispersions of the foregoing type can optionally be stabilized against settling by means of standard non-base emulsifiers, especially nonionic extenders. Such 25 nonionics and their usage levels, have been disclosed in U . S.
Patent 4,454,049, MacGilp, et al., issued June 12, 1984.

Specific examples of nonionic extenders suitable for use in the compositions herein include glycerol esters ( preferably 30 glycerol monostearate), fatty alcohols (e.g., stearyl alcohol), and ethoxylated linear alcohols (preferably Neodol 23-3 - the condensation product of C1 2-C1 3 linear alcohol with 3 moles ethylene oxide, marketed by Shell Chemical Company) and mixtures thereof. Mixtures of glycerol monostearate and Neodol 35 23-3 are particularly preferred. The nonionic, if used, is typically used at a level of from about 0.1~ to about 1 Ogc, by weight of the composition.
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13~6641 Optional Ingredients Fully-formulated fabric softening compositions may optionally contain, in addition to the rapidly biodegradable quaternary 2-hydroxypropyl monoester ammonium compounds of the formula 5 herein, and liquid carrier, one or more of the following in-g redients .
Conventional quaternary ammonium softening agents The compositions of the present invention can further com-prise a conventional di(higher alkyl) quaternary ammonium 10 softening agent. The compositions herein can contain from 0% to about 25% (preferably from about 0.1~ to about 10%) of the con-ventional di(higher alkyl)quaternary ammonium softening agent.
8y "higher alkyl", as used in the context of the conventional quaternary ammonium salts herein, is meant alkyl lS groups having from about 8 to about 30 carbon atoms, preferably from about 11 to about 22 carbon atoms. Examples of such conventional quaternary ammonium salts include:
(i) acyclic quaternary ammonium salts having the formula:

B2 N B3 A~3 wherein B2 jS an acyclic aliphatic C1 5-C22 hydrocarbon group, B3 is a C1-C4 saturated alkyl or hydroxyalkyl group, B is selected from B2 and B3, and A is an anion;
25 (iil diamido quaternary ammonium salts having the formula:
O BS O ~
B 1 _ C - NH - B 2 _ N - B 2 _ NH - C - B 1 A~3 wherein B1 is an acyclic aliphatic C15-C22 hydrocarbon group, B2 is a divalent alkylene group having 1 to 3 carbon - atoms, BS and B8 are C1-C4 saturated alkyl or hydroxyalkyl groups, and A is an anion;
(iii)diamido alkoxylated quaternary ammonium salts having the formula:

-- t2 -O B5 O (~
E~ 1 _ C - NH - B 2 _ N - B 2 _ NH - C - B 1 A~3 ( CH 2CH 2 ) nH
wherein n is equal to from about 1 to about 5, and B1, B2, S B5 and A are as defined above;
liv) quaternary imidazolinium compounds having the formula:

~1 ~B2 o ~i3 1 o L ~ --CH2CH2 ZCB 1 A~) wherein Bl = C15-C17 saturated alkyl, B = Cl-C4 saturated alkyl or H, ~ = NH or O, and A is an anion.
Examples of Component (i) are the well-known dialkyldi-methylammonium salts such as ditallowdimethylammonium chloride, ditallowdimethylammonium methylsulfate, di(hydrogenated tallow) dimethylammonium chloride, dibehenyldimethylammonium chloride.
Examples of Components (ii) and (iii) are methylbis(tallow-amidoethyl) (2-hydroxyethyl) ammonium methylsulfate and methyl-bis(hydrogenated tallowamidoethyl) (2-hydroxyethyl) ammonium methylsulfate, wherein B1 is an acyclic aliphatic C15-C17 hydro-carbon group, B is an ethylene group, 85 is a methyl group, ~8 is a hydroxyalkyl group and A is a methylsulfate anion; these materials are available from Sherex Chemical Company under the trade names Varisoft~ 222 and Varisoft~ 110, respectively.
Examples of Component (iv) are t-methyl-l-tallowamino-ethyl-2-tallowimidazolinium methylsulfate and l-methyl-l-(hydrogenated tallowamidoethyl)-methylsulfate.
Free amines The liquid compositions herein should be substantially free (generally less than about 1%) of free (i.e., unprotonated) amines .
Minor amounts of protonated amines, typically from about û. 05~ to about 1 . 0~, namely primary, secondary and tertiary amines having, at least, one straight-chain organic group of from about 12 to about 22 carbon atoms may be used in the compositi~ns of the present invention to enhance dispersion 131~6~1 stability. Preferred amines of this class are ethoxyamines, such as monotallow-dipolyethoxyamine, having a total of from about 2 to about 30 ethoxy 9 roups per molecule . Also suitable are diamines such as tallow-N,N', N'-tris (2-hydroxyethyl)-1,3-propylenedi-5 amine, or Cl6-cl8-alkyl-N-bis(2-hydroxyethyl)amines- Examples of the above compounds are those marketed under the trade names GENAMIN C, S, O and T, by Hoechst.
Care must be taken that if minor amounts of these amines are used to enhance the dispersion stability of the compositions, 10 they are protonated with acid during formulation, otherwise the free amines may catalyze decomposition of the biodegradable quaternary ammonium compounds during storage.
Di-(higher alkyl) cyclic amine The compositions herein optionally comprise from 0% to about !5 25% (preferably from about O. t~- -to about 10~) by weight of the composition of a di(higher alkyl) cyclic amine fabric softening agent of the formula:
(CH21n (~ N - X - B2 ~;C~

wherein n is 2 or 3, preferably 2; B and B2 are, independently, a C8-C30 alky1 or alkenyl, preferably C1 1-C22 alkyl, more pref-erably C15-C18 alkyl, or mixtures of such alkyl radicals. Exam-25 ples of such mixtures are the alkyl radicals obtained from coconutoil, "soft" (non-hardened) tallow, and hardened tallow. Q is CH
or N, preferably N. X is B4 - T - C -owherein T is O or NB5, B5 being U or C1-C4 alkyl, preferably 30 H, and B is a divalent C1-C3 alkylene group or (C2H4O)m, wherein m is from about 1 to about 8.
Silicone Component The fabric softening compositions herein optionally contain an aqueous emulsion of a predominantly linear polydialkyl or alkyl 35 aryl siloxane in which the alkyl groups can have from one to five carbon atoms and may be wholly or partially fluorinated. These - 14 - 1 3 i 6~ ~i siloxanes act to provide improved fabric feel benefits. Suitable silicones are polydimethyl siloxanes having a viscosity, at 25C, of from about 100 to about 100,000 centistokes, preferably from about 1,000 to about 12,000 centistokes.
It has been found that the ionic charge characteristics of the silicone as used in the present invention are important in deter-mining both the extent of deposition and the evenness of distri-bution of the silicone and hence the properties of a fabric treated therewi th .
Silicones having cationic character show an enhanced tenden-cy to deposit. Silicones found to be of value in providing fabric feel benefits have a predominantly linear character and are preferably polydialkyl siloxanes in which the alkyl group is most commonly methyl. Such silicone polymers are frequently man-ufactured commercially by emulsion polymerization using a strong acid or strong alkali catalyst in the presence of a nonionic or mixed nonionic anionic emulsifier system. In addition to providing improved fabric feel benefits, the sillcone components also improve the water absorbency of the fabrics treated with the softening compositions herein.
The optional silicone component embraces a silicone of cat-ionic character which is defined as being one of;
(a) a predominantly linear di-C1-C5 alkyl or C1-C5 alkyl aryl siloxane, prepared by emulsion polymerization using a cationic or nonionic surfactant as emulsifier;
(b) an alpha-omega-di-quaternized di-C1-C5 alkyl or C1-C5 alkyl aryl siloxane polymer; or lc) an amino-functional di-C1-C5 alkyl or alkyl aryl siloxane polymer in which the amino group may be substituted and may be quaternized and in which the degree of substitution (d . s. ) lies in the range of from about 0.0001 to about 0.1, preferably from about 0.01 to about 0. 075 provided that the viscosity at 25C of the silicone is from about 100 to about 100,000 es.

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-13166~1 The fabric softening compositions herein may contain up to about 15%, preferably from about 0.1~ to about 10~, of the sili-cone component.
Thickening Agent S Optionally, the compositions herein contain from 096 to about 3~, preferably from about 0.01% to about 2%, of a thickening agent. Examples of suitable thickening agents include: cellulose derivatives, synthetic high molecular weight polymers (e.g., carboxyvinyl polymer and polyvinyl alcohol ), and cationic guar gums.
The cellulosic derivatives that are functional as thickening agents herein may be characterized as certain hydroxyethers of cellulose, such as Methocel@), marketed by Dow Chemicals, Inc.;
also, certain cationic cellulose ether derivatives, such as Polymer JR-125~, JR-400~, and JR-30~), marketed by Union Carbide.
Other effective thickening agents are cationic guar gums, such as Jaguar Plus (E3, markéted by Stein Halt, and Gendrive 458~, marketed by General Mills.
Preferred thickening agents herein are selected from the group consisting of methyl cellulose, hydroxypropyl methyl-cellulose, hydroxybutyl methylcellulose, or mixtures thereof, said cellulosic polymer having a viscosity in 29~ aqueous solution at 20C of from about 15 to about 75,000 centipoise.
Soil Release Agent Optionally, the compositions herein contain from 0~ to about 10%, preferably from about ~.2% to about 5~, of a soil release agent. Preferably, such a soil release agent is a polymer, Polymeric soil release agents useful in the present invention include copolymeric blocks of terephathalate and polyethylene oxide or polypropylene oxide, and the like.
A preferred soil release agent is a copolymer having blocks of terephthalate and polyethylene oxide. More specifically, these polymers are comprised of repeating units of ethylene tere-` phthalate and polyethylene oxide terephthalate at a molar ratio of ethylene terephthalate units to polyethylene oxide terephthalate units of from about 25:75 to about 35:65, said polyethylene oxide - 16 - 1 3 1 ~ 6 ~ 1 terephthalate containing polyethylene oxide blks having molecu-lar weights of from about 300 to about 2000. The molecular weight of this polymeric soil release agent is in the range of from about 5,000 to about 55,000.
Another preferred polymeric soil release agent is a crystal-lizable polyester with repeat units of ethylene terephthalate units containing from about 10% to about 15~ by weight of ethylene terephthalate units together with from about 10% to about 50% by weight of polyoxyethylene terephthalate units, derived from a polyoxyethylene glycol of average molecular weight of from about 300 to about 6, 000, and the molar ratio of ethylene terephthalate units to polyoxyethylene terephthalate units in the crystallizable polymeric compound is between 2:1 and 6:1. Examples o~ this polymer include the commercially available materials Zelcon@~ 4780 (from Dupont) and Milease~ T (from ICI).
Highly preferred soi I release agents are polymers of the generic formula:
O O O O
2 ll 1 tl X-lOCH2CH2)n~0-C-B -C-OB 1U(O-C-B -C-O) (CH2CH20-)n-X
in which X can be any suitable capping group, with each X being selected from the group consisting of H, and alkyl or acyl groups containing from about 1 to about 4 carbon atoms. n is selected for water solubility and generally is from about 6 to about 113, preferably from about 20 to about 50. u is critical to formulation in a liquid composition having a relatively high ionic strength.
There should be very little material in which u is greater than 10. Furthermore, there should be at least 20%, preferably at least 40%, of material in which u ranges from about 3 to about S.
The Bl moieties are essentially 1 ,4-phenylene moieties. As used herein, the term "the B moieties are essentially 1,4-phenylene moieties" refers to compounds where the Bl moieties consist entirely of 1,4-phenylene moieties, or are partially sub-stituted with other arylene or alkarylene moieties, alkylene moieties, alkenylene moieties, or mixtures thereof. Arylene and alkarylene moieties which can be partially substituted for 1,4-13166~

phenylene include 1, 3-phenylene, 1, 2-phenylene, 1, 8-naphthylene, 1,4-naphthylene, 2,2-biphenylene, ~,4-biphenylene and mixtures thereof. Alkylene and alkenylene moieties which can be partially substituted include ethylene, 1,2-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexamethylene, 1,7-heptamethylene, 1,8-octamethylene, 1,4-cyclohexylene, and mixtures thereof.
For the B1 moieties, the degree of partial substitution with moieties other than 1, 4-phenylene should be such that the soll release properties of the compound are not adversely affected to any great extent. Generally, the degree of partial substitution which can be tolerated will depend upon the backbone length of the compound, i.e., longer backbones can have greater partial substitution for 1 ,4-phenylene moieties. Usually, compounds where the B1 comprise from about 50% to about 100%
1,4-phenylene moieties (from 0 to about 50~ moieties other than 1 ,4-phenylene1 have adequate soil release activity. ~or example, polyesters made accordirg to the present invention with a 40:60 mole ratio of isophthalic ( 1 ,3-phenylene) to terephthalic (1,4-phenylene) acid have adequate soil release activity.
However, because most polyesters used in fiber making comprise ethylene terephthalate units, it is usually desirable to minimize the degree of partial substitution with moieties other than 1,4-phenylene for best soil release activity. Preferably, the B1 moieties consist entirely of (i.e., comprise 100%) 1,4-phenylene moieties, i . e., each B 1 moiety is 1, 4-phenylene.
For the B2 moieties, suitable ethylene or substituted ethylene moieties include ethylene, 1,2-propylene, 1,2-butylene, 1,2-hexylene, 3-methoxy-1,2-propylene and mixtures thereof.
Preferably, the B2 moieties are essentially ethylene moieties, 1, 2-propylene moieties or mixture thereof . Inclusion of a greater percentage of ethylene moieties tends to improve the soil release activity of compounds. Surprisingly, inclusion of a greater percentage of 1,2-propylene moieties tends to improve the water solubility of the compounds.
Therefore, the use of 1, 2-propylene moieties or a simi lar branched equivalent is desirable for incorporation of any - - 18- 13~6~1 substantial part of the soil release component in the liquid fabric softener compositions. Preferably, from about 75% to about 100%, more preferably from about 90~ to about 100~, of the 82 moieties are 1,2-propylene moieties.
The value for each n is at least about 6, and preferably is at least about 10. The value for each n usually ranges from about 12 to about 113. Typically, the value for each n is in the range of from about 12 to about 43.
A more complete disclosure of these highly preferred soil release agents is contained in European Patent App1ication 185,427, Gosselink, published June 25, 1986.

Viscosity Control Agents Viscosity control agents can be used in the compositions of the present invention (preferably in concentrated compositions).
Examples of organic viscosity modifiers are fatty acids and esters, fatty alcohols, and water-miscible solvents such as short chain alcohols. Examples of inorganic viscosity control agents are water-soluble ionizable salts. A wide variety of ionizable salts can be used. Examples of suitable salts are the halides of the group IA and I IA metals of the Periodic Table of the Elements, e.g., calcium chloride, magnesium chloride, sodium chloride, potassium bromide, and lithium chloride. Calcium chloride is preferred. The ionizable salts are particularly useful during the process of mixing the ingredients to make the compositions herein, and later to obtain the desired viscosity. The amount of ionizable salts used depends on the amount of active ingredients used in the compositions and can be adjusted according to the desires of the formulator. Typical levels of salts used to control the composition viscosity are from about 20 to about 3, 000 parts per million [ppm), preferably from about 20 to about 2,000 ppm, by weight of the composition.
Bactericides Examples of bactericides used in the compositions of this invention include glutaraldehyde, formaldehyde, 2-bromo-2-nitro-propane-1,3-diol sold by Inolex Chemicals under the trade name ~.
~i :

1316~1 Bronopol~), and a mixture of S-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazoline-3-one sold by Rohm and Haas Company under the trade name Kathon~ CG/ ICP. Typical levels of bacteriocides used in the present compositions are from about 1 to about t,000 ppm by weight of the composition.
Other Optional Ingredients The present invention can include other optional components conventionally used in textile treatment compositions, for example, colorants, perfumes, preservatives, optical brighteners, opacifiers, fabric conditioning agents, surfactants, stabilizers such as guar gum and polyethylene glycol, anti-shrinkage agents, anti-wrinkle agents, fabric crisping agents, spotting agents, germicides, fungicides, anti-oxidants such as buty1ated hydroxy toluene, anti-corrosion agents, and the like.
In the method aspect of this invention, fabrics or fibers (including hair) are contacted with an effective amount, generally from about 20 ml to about 300 ml (per 3. S kg of fiber or fabric being treated), of the compositions herein in an aqueous bath.
Of course, the amount used is based upon the judgment of the user, depending on concentration of the composition, fiber or fabric type, degree of softness desired, and the like. Typically, about 120 mls. of a 5% dispersion of the softening compounds are used in a 25 1 laundry rinse bath to soften and provide antistatic benefits to a 3.5 kg load of mixed ~abrics. Preferably, the rinse bath contains from about 25 ppm to about 100 ppm of the fabric softening compositions herein.
Solid carrier materials can be used in place of liquids. For example, the softener compounds herein can be absorbed on particulate solids such as potassium suîfate, micronized silica, powdered urea, and the like, and added to a laundry rinse bath.
Alternatively, the softeners can be releasably padded onto a sheet (e.g., paper toweling, nonwoven fabric, or the like) and tumbled with damp fabrics in a hot-air clothes dryer, in the manner of the E~OUNCE~) brand dryer-added product known in commercial practice. Generally, such solid-form compositions will comprise from about 1% to about 20% of the quaternized ester-ammonium 13~fi6~

softening compound, and from about 75% to about 99~ of the solid carrier .
The following examples illustrate the practice of the present invention but are not intended to be limiting thereof.
EXAMPLE I
A storage stable biodegradable fabric softening composition of the present invention is made as foliows:
Ingredient Percent (wt. ) -OH o (CH3)2- ~N-CH2-cH-cH2Oc C17 35 Cl 8H37 I sopropanol 1 . Q9 B ronopol 0 . 019~
Dye 20 ppm 0.1 N HCI 0. 25%
Water - Balance 20 g of the biodegradable monoester ammonium softener com-pound and 5 9 of isopropanol are mixed and heated to 80C to form a fluidized "melt". The molten mixture is then poured into a 20 400 g water seat with high shear mixing. The water is preheated to 70C, and 20 ppm blue dye and 100 ppm bronopol are added to the water prior to mixing. About 1 9 of isopropanol is evaporated from the molten mixture before it is poured into the water. The dispersion is mixed for 25 minutes at 7000 rpm 25 (Tekmar high shear mixer). During mixing the temperature of the dispersion is maintained within 70-75C by a cooling water bath. The pH is adjusted by the addition of 1 ml of 0.1 N HCI.
The resulting dispersion has a viscosity of 50 centipoise (at 25C), a pH of 3.5, and contains less than 1% of free (i.e..
30 unprotonatedl amines. The average particle size in the dispersion is 0. 20 microns .
EXAMPLE i I
A storage stable biodegradable fabric softening composition of the,present invention is made as follows:

Ingredient Percent (wt. ) OH O
(CH3)2- N-cH2-cH-cH2oc-cl7H35cl S.096 Cl 8H37 I sopropanol 1 . 1%
Glyceryl Monostearate (GMS) 1~
Neodol 23-3 196 0.1 N HCI 0.25%
Water Balance 20 9 of the biodegradable monoester ammonium softener com-pound and 5 g of isopropanol are mixed and heated to 6ûC to form a fluidized "melt". 4 9 of GMS and ~ g of Neodol 23-3 are then added to the melt to form a homogeneous molten mixture.
The molten mixture is then poured into a 365 g water seat with high shear mixing . The water is preheated to 50C. 0. 6 9 of isopropanol is evaporated from the molten mixture before it is poured into the water. The dispersion is mixed for 20 minutes at 7200 rpm (Tekmar high shear mixer). The pH is adjusted by the addition of 1 ml of 0.1 N HCI. The resulting dispersion has a viscosity of 48 centipoise (at 25C), a pH of 3 . 5, and contains less than 196 of free (i.e., unprotonated) amines. The average particle size is 0.17 micron.
EXAMPLE l l I
A storage stable biodegradable fabric softening composition of the present invention is made as follows:
Ingredient Percent (wt.
OH o (CH ) -~N-CH2-CH-CH2OC-C1 7H35 I sopropanol 0 . 6 Glyceryl Monostearate ( GMS ) 1 . 2 Neodol 23-3 0 . 3 Polydimethylsiloxane (PDMS) 0.1 0.1 N HCI 0. 25~
Water Balance 13166~1 18 g of the biodegradable monoester ammonium softener compound and 2.4 g of isopropanol are mixed and heated to 70C
to form a fluidized "melt". 4.8 9 of ~:iMS and 1.2 9 of Neodol 23-3 are then added to the melt to form a homogeneous molten 5 mixture. The n~olten mixture is then poured into a 375 g water seat with high shear mixing. The water is preheated to 65C.
The dispersion is mixed for 15 minutes at 7000 rpm (Tekmar high shear mixer). After the dispersion cools down to about 30C, 0.4 g of PDMS is added to the dispersion with low shear mixing ( 3000 10 rpm for 3 minutes ) . The pH is adjusted by the addition of 1 ml of 0 1 N HCI. The resulting dispersion has a viscosity of 88 centipoise (at 25C), a pH of 3.9, and contains less than 19~ free (i.e., unprotonated) amines. The average particle size in the dispersion is 0.19 microns.
EXAMPLE IV
A storage stable biodegradable concentrated fabric softening composition of the present invention is made as ollows:
Ingredient Percent (wt. ) O H O
20 ( ~:H ) - N-CH2-CH-CH20C-C~ 7H35C
C~ 8H37 I sopropanol 2.5~
Glycerol Monostearate (GMS) 1. 0%
Neodol 23-3 0. 5%
- 25 CaC12 0. 06 0.1 N HCI 0. 25~
Water Balance 30 9 of the biodegradable monoester ammonium softener compound and 5 g of isopropanol are mixed and heated to 75C to 30 form a fluidized melt. 2 9 of GMS and 1 9 of Neodol 23-3 are then added to the melt to form a homogeneous molten mixture.
The melt is then poured intô a 165 9 water seat with high shear mixing. The water is preheated to 60C. The dispersion is -- mixed for 15 minutes at 7000 rpm ~Tekmar high shear mixer). 6 35 ml of 2~ CaC12 aqueous solution is added to the dispersion during mixing to prevent the dispersion from gelling. During mixing the - 23 - 1 31~ 6 ~ 1 dispersion's tempera~ure is maintained at about 60C. The pH is adjusted by the addition of 0. S mi of 0.1 N HCI. The resulting dispersion has a viscosity of 210 centipoise (at 25C), a pH of 3.8, and conta.ns less than 1% free (i.e., unprotonated) amines.
The average particle size in the dispersion is 0. 26 microns.
In a convenient mode, this concentrated composition is packaged in a simple plastic pouch, which is opened and poured into 4X its volume of water prior to use to prepare a "single strength" softener composition, thereby saving on packaging and shipping costs, as well as storage space.
Typically, the liquid fabric softening compositions in the above examples are added to the rinse cycle of conventional washing machines. When multiple rinses are used, the fabric softening composition is preferably added to the final rinse. ~he amount added to the rinse cycle is generally from about 20 ml to about 300 ml lper 3 . 5 kg of fabric being treated ) of the compositions of Examples l-lll (and the diluted version of Examplé
IVl .
E XAM PLE V
The preparation of a fabric-softener sheet for use in a hot-air clothes dryer is as follows.
Fabric Conditioning Composition ComponentsPercent (wt. ) OH O
+
3)2 ~ -cH2-cH-cH2oc-c1 7H35CH3S4 46. 0 Cl 8H37 Sorbitan Monostearate 46 . 0%
Clay 7 . 0%
Perfume 1. 0 Dryer-added Sheet Substrate Composition Rayon fibers 70 . 0~
Polyvinyl acetate 30. 0%
(10"x14" (25.4 cm x 35.6 cm3 sheets, 1.4 gm) The biodegradable monoester ammonium softener compound, sorbitan monostearate, clay ( Bentolite L, a montmorillonite clay, - 24 - 13166~
obtained from Southern Clay Products), and perfume are mixed and heated to 80C to form a fluidi2ed "melt". The substrate (made of the rayon fibers with polyvinyl acetate) is then coated with about 4 grams of the molten actives and dried overnight.
This provides a weight ratio of fabric conditioning composition:dry substrate of approximately 3.
Following solidification of the fabric conditioning composition, the substrate is slit with a knife, said slits being in substantially parallel relationship and extending to within about 1 inch t2.5 cml from at least one edge of said substrate. The width of an individual slit is approximately 0.2 inches (0.5 cm). These dryer added sheets are added to a clothes dryer together with damp fabrics to be treated (typically, one sheet per 3.5 kg load of fabrics, dry weight basis). The heat and tumbiing action of the revolving dryer drums evenly distributes the composition over all fabrics, and dries the fabrics. Fabric softening and static control are provided to the fabrlcs in this manner.
In all of the above examples, substantially similar results are obtained when the biodegradable quaternary monoester ammonium softening compound is replaced, Tn whole or in part, with any of the following biodegradable monoester ammonium softening compounds:
18H37J~NcH2cH(oH)cH2oc(o)cl7H3sBr~3 3l2lc16H33]~hcH2cH(oH)cH2oc(o)c15H3 2S 2 5l2lcl8H35]6hcH2cH(oH)cH2oc(o)clsH3lc~
2 51l 31[C18H3~I NCH2CH(OH)CH20C(O)C17H35CH SO ~3 3 7]l 2 51[Cl6H331~hcH2cH(oH)cH2oc(o)clsH3lc liso-c3H7]lcH3llc18H37l~NcH2cH(oH)cH2oc( ) 15 31 Importantly, the above biodegradable liquid compositions 30 (Examples l-IV) display excellent softening characteristics on both natural and synthetic fabrics, low viscosity at both normal and elevated temperatures, and good product stability and dispersibility .

Claims

1. A liquid fabric softening and antistatic composition comprising:
(a) from about 1% to about 20% by weight of submicron-sized particles of a quaternized ester-ammonium softening compound having the formula and mixtures thereof, wherein each R substituent is independently selected from C1-C6 alkyl, alkenyl or hydroxyalkyl groups, R1 is a C14-C22 hydrocarbyl group, R2 is a C13-C21 hydrocarbyl group and, A is a softener compatible anion; and (b) from about 60% to about 98% of a liquid carrier having said softening compound particles dispersed therein; said composition being maintained at a pH ranging from about 2.0 to about 5.0 and further being substantially free of unprotonated amines.

2. A composition according to claim 1 wherein each R substituent is C1-C3 alkyl, R1 is C16-C18 alkyl, and R2 is C13-C17, alkyl.

3. A composition according to claim 2 wherein each R substituent is methyl.

4. A composition according to claim 3 which contains from about 2%
to about 10% of the softening compound.

5. A composition according to claim 1 which is formulated at a pH of about 3.0?0.5.

6. A composition according to claim 2 wherein the liquid carrier consists of a mixture of (i) C1-C4 monohydric alcohol or mixtures thereof; and (ii) water;
the amount of monohydric alcohol being from about 5% to about 50% by weight of the softening compound.

7. A composition according to claim 6 wherein the particles have an average diameter of from 0.1 to about 0.5 micron.

8. A composition according to claim 7 wherein the monohydric alcohol is isopropanol.

9. A composition according to claim 1 which additionally contains from about 0.1% to about 10% of a conventional di-(higher alkyl) quaternary ammonium softening agent.

10. A composition according to claim 1 which additionally contains from about 0.1% to about 10% by weight of a nonionic extender.

11. A composition according to claim 10 wherein the nonionic extender is selected from the group consisting of glycerol esters, fatty alcohols, ethoxylated linear alcohols, and mixtures thereof.

12. A composition according to claim 5 wherein the quaternized ester-ammonium softening compound is

13. A composition according to claim 1 in concentrated form which contains from about 11% to about 20% of the softening compound.

14. A composition according to claim 13 which additionally contains from about 20 to about 3,000 ppm of a salt selected from the group consisting of calcium chloride, magnesium chloride, sodium chloride, potassium chloride, lithium chloride, and mixtures thereof.

15. A composition according to claim 14 wherein the salt is calcium chloride.

16. A method of softening and providing an antistatic finish to fabrics by contacting said fabrics with an effective amount of the composition of claim 1.